The Hat Man

The series'd serialized in parts since 1988. Nemurenai and Komori-uta series've serialized in (mainly) Morning and released as 2 volumes by Kodansha. In 2009, 3 new chapters (the chapters under Nido Shinu title in the all-in-one volume) serialized in Comic Beam from 5/2009 to 7/2009 and all of the chapters (including the Kodansha ones) published in one single volume as Boushi Otoko.

In the Boushi Otoko series:

1. Boushi Otoko wa Nemurenai (by Kodansha in 1993)
2. Boushi Otoko no Komori-uta (by Kodansha in 1996)
3. Boushi Otoko wa Nido Shinu (Published in Comic Beam in '09)